ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The quantum efficiency of HgCdTe photodiodes in relation to the direction of illumination and to their geometry (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3034-3040 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this paper a theoretical study of the effect of the direction of the incident light on the quantum efficiency of homogeneous HgCdTe photodiodes suitable for sensing infrared radiation in the 8–12 μm atmospheric window is presented. The probability of an excess minority carrier to reach the junction is derived as a function of its distance from the edge of the depletion region. Accordingly, the quantum efficiency of photodiodes is presented for two geometries. In the first, the light is introduced directly to the area in which it is absorbed (opaque region), while in the second, the light passes through a transparent region before it reaches the opaque region. Finally, the performance of the two types of diodes is analyzed with the objective of finding the optimal width of the absorption area. The quantum efficiency depends strongly on the way in which the light is introduced. The structure in which the radiation is absorbed following its crossing the transparent region is associated with both higher quantum efficiency and homogeneity. In addition, for absorption region widths higher than a certain minimum the quantum efficiency in this case is insensitive to the width of the absorption region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    On the extraction of linear and nonlinear physical parameters in nonideal diodes (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 6873-6883 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We describe a parameter extraction technique for the simultaneous determination of physical parameters in nonideal Schottky barrier, p-n and p-i-n diodes. These include the ideality factor, saturation current, barrier height, and linear or nonlinear series, and parallel leakage resistances. The suggested technique which deals with the extraction of bias independent parameters makes use of the forward biased current–voltage (I–V) characteristics and the voltage-dependent differential slope curve α(V)=[d(ln I)]/[d(ln V)]. The method allows (a) establishment of the current flow mechanisms at low and high bias levels, (b) extensive of the permissible ranges of determined parameters beyond what is possible in other published methods, and (c) to automation and computerization of the measurement processes. The method is verified experimentally using metal–semiconductor structures based on Si, InGaP, and HgCdTe as well as an InGaAs/InGaAsP multiple quantum well laser diode exemplifying a p-n junction. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.370206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The effects of built-in electric field on the performance of compositionally graded P-on-n HgCdTe heterojunction photodiodes (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 925-933 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The results of a study of the optical and electrical performance of P-on-n HgCdTe heterojunctions, with a linear gradient in composition, are presented. First presented is a solution of the one-dimensional continuity equation which includes the spatial dependencies of the material properties, such as absorption coefficient, band gap, and intrinsic carrier concentration, in the graded layer. Using the above solution, diodes with different grading profiles (and hence different electric fields), but with the same cutoff wavelength, are compared. The advantages of the built-in electric field formed by the grading in composition are presented and discussed. It is shown that the major consequence of the electric field is the reduction of the effects caused by the imperfect CdTe/HgCdTe interface at the backside. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359020
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Quantum efficiency and spectral response of compositionally graded HgCdTe P-n heterojunction photodiodes (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4399-4406 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Results are presented of a study of the quantum efficiency of HgCdTe heterojunction photodiodes. All heterojunctions considered in the study consist of a wide-band-gap P-type layer and a narrow-band-gap n-type layer, and are illuminated from the backside. The n-type layer is compositionally graded and therefore contains a built-in electric field. Due to the difference in band gaps photons are absorbed in the active n-type layer only and are collected by both drift and diffusion mechanisms. The one-dimensional continuity equation is first solved in the linearly graded n-type region under illumination conditions, and then the dependence of the quantum efficiency on the resulting built-in electric field is presented. Two different modes of illumination are compared: In the first mode, associated with n-on-P HgCdTe diodes, the light reaches the transparent P layer first; in the second mode, associated with P-on-n diodes, the light reaches the transparent P side after it passes through the opaque n-type layer. The superiority of the first mode is demonstrated: It consistently renders higher quantum efficiencies, and is also less sensitive to several properties of the diode such as the width of the absorbing layer and the quality of the backside interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357333
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Polarization dependence of spectral transmission and photoconductive response of a p-doped multiple quantum well structure (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 1998-2000 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A comparison between the optical transmission and the photoconductive response of p-type quantum well infrared photodetectors is demonstrated. The dependence on polarization was found to be different for these two processes. Light polarized perpendicular to the growth layers was more efficiently absorbed by the quantum wells, while the photoconductive response was stronger for the parallel polarized light. The difference is attributed to the different vertical transport behavior of light and heavy holes and the mixed nature of hole subbands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357667
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Vertical drift mobility of excited carriers in multi quantum well structures (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 3536-3543 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the vertical mobility of photo-excited carriers in quantum well infrared detectors are reported. The low temperature mobility is extracted by means of a photo geometrical magnetoresistance technique. This approach is most suitable for the multi quantum well structure geometry. Both rectangular and stepped well structures were studied. They exhibit asymmetry with regard to bias polarity for both gain and mobility. This asymmetry is shown to be contributed by both well structure, and growth induced inequivalent interfaces. The low field mobility is governed mainly by unscreened ionized impurity scattering in the barriers. The well interfaces act as additional anisotropic scattering centers. We observe clear correlation between the extracted drift velocity and the optical gain. It is postulated that anisotropic well recapture causes polarity dependent energy distribution above the barriers. In addition, we conclude that intervalley scattering of the hot electrons has a substantial influence on the detector performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Calculation of semiconductor intrinsic properties using a nonparabolic three-band model (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 411-413 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The intrinsic carrier concentration and the Fermi level are calculated using an approximation of the three-band k⋅p model. The approach is suitable for temperatures from 0 to 400 K and includes the contribution of electrons in the lowest conduction band, heavy holes, and light holes. An approximation for the nonparabolic Fermi–Dirac integral is used in the calculation of carrier concentrations. The resulting expressions are simple and depend explicitly on temperature, semiconductor band gap, carrier effective masses, and nonparabolicity factors. Consequently, the present approach seems suitable for the calculation of intrinsic properties of any semiconductor material for which the three-band k⋅p model is applicable. The model is compared with a numerical integration of the k⋅p model for Hg1−xCdxTe (0.17〈x〈1) and with experimental measurements (0.2〈x〈0.29). We also present a comparison between the model and a numerical evaluation of the three-band model for InGaAs. Because of their simplicity the new expressions seem suitable for both numerical and analytical modeling of semiconductor devices and materials. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359341
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Electronic properties of metal/sol-gel SiO2/indium-phosphode capacitor (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 1314-1316 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This work reports on the electrical properties of metal-oxide-semiconductor (MOS) capacitors made with a spin-on-glass (SOG) SiO2 layer, doped with 2% phosphorus, deposited on InP substrate by spin casting followed by a low-temperature (〈260 °C) anneal. The capacitance versus voltage behavior as well as the dielectric constant of the SOG layer was analyzed as a function of the frequency. The stability of the relevant parameters was checked after a long period of time (four weeks), compared with fresh devices, and revealed a significant increase in the dielectric constant and a slight increase in the leakage current. It is shown that the use of SOG as the dielectric material in the MOS structure leads to a relatively low fixed charge (less than 2×1011 cm−2) and low fast state concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104295
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Intersublevel transitions in InAs/GaAs quantum dots infrared photodetectors (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2003-2005 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thermal generation rate in quantum dots (QD) can be significantly smaller than in quantum wells, rendering a much improved signal to noise ratio. QDs infrared photodetectors were implemented, composed of ten layers of self-assembled InAs dots grown on GaAs substrate. Low temperature spectral response shows two peaks at low bias, and three at a high one, polarized differently. The electronic level structure is determined, based on polarization, bias, and temperature dependence of the transitions. Although absorbance was not observed, a photoconductive signal was recorded. This may be attributed to a large photoconductive gain due to a relatively long lifetime, which indicates, in turn, a reduced generation rate. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.122349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Lifetime and carrier-concentration profile of B+-implanted p-type HgCdTe (1986)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 60 (1986), S. 3916-3922 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The lifetime and carrier-concentration profile of Hg1−xCdxTe photodiodes (x=0.2–0.3) formed by implantation of B+ ions (100 keV, 1013–1014 cm−2) into a p-type substrate was investigated. Using graded C-V measurements, concentration of carriers around the n+p junction was obtained. It was found that the junction is located at a depth of 0.7–1.5 μm, depending on the bulk hole concentration. The technique enables profiling of the same sample after annealing. The annealing process was shown to make the electron concentration shallower and thus to bring the junction closer to the surface. Various techniques were used to measure excess carrier lifetimes. All indicate that the extent of degradation of the excess electron lifetime in the p region is very limited. For all tested samples, an etch of 2 μm was enough to recover the bulk lifetime. These results contradict the general assumption of deep damages in the p-type substrate. Thus, the contribution of the n+ side to the saturation current and to the R0A product cannot be neglected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.337514
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...